LOS ANGELES (AP)  The Los Angeles fire chief said his department has experienced a series of recent “divisive” workplace incidents, including at least one debate between firefighters over protests by NFL players.

In a letter posted last week on the LAFD”s internal messaging system, Chief Ralph Terrazas wrote that he expects all firefighters to contribute to a respectful workplace free of discrimination, harassment, retaliation and hazing.

Terrazas said there have been on-duty heated discussions about NFL players who kneeled during the national anthem. In a separate incident, he wrote, the department received complaints about “a perceived lack of sensitivity” toward non-white firefighters during an investigation.

The Los Angeles Times reported Tuesday that the letter drew praise from Fire Commission President Delia Ibarra, who said it offered a reminder to employees to be respectful when discussing politics.